While the avalung has certainly been responsible for saving lives, I’m not giving this integrated version high marks. The reason is “it depends”. It depends on the pack you get! Do you feel lucky? Our ski patrol uses this pack and approximately 1/3 of the integrated avalung units resonate significantly when breathing in or out of the mouth piece. Many describe this noise as a “mating elephant” or other such funny description, but I don’t find the issue amusing when try to use it. Another approximately 1/3 state it resonates sporadically and the last 1/3 claim it works great (quite and smooth).
I’m an experienced open and closed circuit SCUBA user and I am very comfortable breathing through a mouth piece. It became quickly apparent however that when the avalunge became a resonance chamber the air flow was significantly diminished – making it much more difficult to breath. As a comparison, a smaller diameter snorkel with clean air flow is very easy to breath through. Skiing through heavy powder with this thing in your mouth, you are not able to keep up with the oxygen demand. And the whole reason for a mouth piece is to be IN your mouth when skiing suspicious slopes (so says the BD engineers) – so this negates the entire purpose of the unit!
The issue seems to be with the box at the left shoulder – the manifold unit. After calling BD about this, the first guy that answered the phone told me it was designed purposely with this noise so you know it was working correctly. How absurd! Tech service responded that this was a ridiculous answer as well. I sent the pack back for inspection and the resonance was confirmed. BD engineers did admit they had a general issue with this design, but claimed it did not restrict air flow. However their testing consists of pass/fail criteria and they have not released data on airflow rate with and without resonance. Yes, you can still breath when the resonance kicks in, but not well. And certainly not well enough to ski or skin with the device in your mouth in heavy powder at higher altitudes. And how about after being buried by an avalanche when your heart is racing and all goes black, most likely dealing with a traumatic injury. Do you think you’re going to want keep breathing through a device that restricts your airflow significantly? They did say they were working on this issue for future designs but had no intensions for recall. A new pack was returned to me but unfortunately it has the same issue. Interestingly my wife’s unit does not have the issue and works very well.
The pack itself is well made and durable. The larger size can easily support a multi-day winter tour. Most of the reviews I see are for the pack, not the avalung. May only comment with the pack itself is that the ski/ice axe loops being too large to accommodate ice axes securely (more for skis). I’m surprised I have not seen more reviews on this resonance issues, but perhaps folks just accept it?
Again, if you feel lucky, buy the unit, but I don’t recommend rolling the dice and parting with your cash for a unit that may or may not operate smoothly if you are using this mainly for avalanche use. Perhaps the stand alone unit operates more smoothly? One man’s opinion.
Credentials (for what it's worth): 10 year senior ski patroller - Central California Sierra Nevada (instructor for avalanche, outdoor medical and winter search and rescue),
